I spend a lot of time as a pharmacist discussing side effects and allergies to drugs. For your own safety, I won’t recommend or dispense a drug until I know your allergy status. I don’t limit the history to drugs—I want to know anything you’re allergic to, be it environmental, food, insects, or anything else. Allergies can create true therapeutic challenges: We can’t dismiss any allergy claim, but as I’ve blogged before, there’s a big gap between what many perceive as an allergy and what is clinically considered a true allergy. My concern is not only avoiding the harm of an allergic reaction, but also avoiding the potential consequences from selecting a suboptimal therapy that may in fact be appropriate. You may need a specific drug someday, so I encourage patients to discuss vague drug allergies with their physician, and request allergist testing as required.

Food allergies can be as real as drug allergies, and are arguably much harder to prevent. We can usually control when we get penicillin. But what about peanuts, eggs, or milk, all of which can also cause life-threatening anaphylaxis? Food allergies seems to be growing: not only anaphylaxis, but more people believe they have some sort of allergy to food. Allergy is sometimes confused with the term “intolerance”, which seems more common, possibly as the availability of “food intolerance testing” grows. Food intolerance testing and screening is particularly popular among alternative practitioners. Testing can take different forms, but generally the consumer is screened against hundreds of food products and food additives. They are then provided with a list of foods they are “intolerant” to. I’ve spoken with consumers who are struggling to overhaul their diet, having been advised that they are actually intolerant to many of their favourite foods. These reports are taken seriously by patients who believe that they’ll feel better if they eliminate these products. In the pharmacy, I’ve been asked to verify the absence of trace amounts of different fillers in medications because of a perceived intolerance. Children may be tested, too, and parents may be given a long list of foods they are told their child is intolerant of. I’ve seen the effects in the community, too. Think going “peanut free” is tough? A public school in my area sent home a list of forbidden food products: dairy, eggs, bananas, tree nuts, peanuts, soy, sesame, flax seed, kiwi, chicken, and bacon. Were these all true allergies? It’s not disclosed. Anaphylactic or not, the parents had informed the school, and the school had banned the food product.

But can a simple blood test actually identify and eliminate food intolerance? That’s the question I wanted to answer.